Best For
- Extremely fast response time
- 12″H profile is thicker than many other latex options we’ve reviewed
- Ethically sourced, organic materials
Considerations
- Significantly higher motion transfer than I’d like to see
- Very high bounce may be less than ideal, depending on performance preference
- Deep sinkage
Our Verdict
The Diamond Sage mattress is a latex organic hybrid that specializes in natural materials and an organic cover.
During our performance tests, this mattress had excellent cooling, extremely deep sinkage, extremely high motion transfer, extremely fast response time, very high bounce, excellent edge support, excellent sex performance, excellent pressure relief, very good off-gassing, and an excellent company score.
Type: Latex Hybrid
Firmness: Medium (5)
In This Review
Performance Tests | Firmness | Support & Sleeping Positions | Design | Materials | Comparisons | FAQs
Performance Tests
At NapLab, we put each mattress to the test.
We test 10 different factors that impact the performance, comfort, and value of the mattress. Testing categories include:
| Test | Rating |
|---|---|
| Cooling | Excellent |
| Sinkage | Extremely Deep |
| Motion Transfer | Extremely High |
| Response Time | Extremely Fast |
| Bounce | Very High |
| Edge Support | Excellent |
| Sex | Excellent |
| Pressure Relief | Excellent |
| Off-Gassing | Very Good |
| Company | Excellent |
Cooling Test
Cooling performance on the Diamond Sage natural organic hybrid is excellent. In our tests, I felt no significant level of heat retention around my body.
Baseline Temp.
80.2° F
Max Temp.
90.2° F
Ending Temp.
83.7° F
The mattress did a nice job of breathing, keeping the surface of the mattress comfortably cool. The Diamond Sage uses a proven material and layer design of latex comfort layers on top of a pocketed coil base.
Natural latex doesn’t retain significant levels of heat and it’s able to breathe well. Meanwhile, the pocketed coil layer is mostly air, which creates ample airflow into and out of the mattress.
Max Temp.
Ending Temp
- Baseline Temperature – the temperature of the mattress before anyone lies on it
- Maximum Temperature (0 minute) – the temperature of the mattress after lying on it for 15 minutes
- Ending Temperature (5 minute) – the temperature of the mattress after being lied upon and having no one on it for 5 minutes
Looking at our objective data, we saw a consistent and steady temperature decline across the 5 minute measurement period.
From minute 0 to minute 5 the temperature declined 6.5° F. This is 0.1° more decline than the average 5-minute temperature decline of 6.4°.
When we consider the objective temperature data, subjective experience, and material construction, I am confident that most sleepers will find the Diamond Sage to be comfortably cool.
Heat Dissipation Over Time
| Time Elapsed | Temperature |
|---|---|
| 1 minute | 87.0° |
| 2 minutes | 85.5° |
| 3 minutes | 84.5° |
| 4 minutes | 84.6° |
| 5 minutes | 83.7° |
Sinkage Test
The Diamond Sage has an extremely deep level of sinkage. In our tests, we measured a total sinkage depth of 2.91”.
This is 0.67” deeper sinkage than the average sinkage depth of 2.24”.
The Sage has a 4.0” comfort layer with a very soft 1.0” quilted cover and soft 2.0” natural latex layer immediately below that. These top 3.0” give way to pressure quite easily, creating a deeper sinkage depth.
The level of sinkage is documented in the image below.
The mattress has a more generalized hug and contour around the body (which is a product of the latex comfort layers). When you combine this with the deeper level of sinkage the total contour dynamic is more dramatic than many other latex mattresses.
While some sleepers may not love the deeper sinkage, the depth of sinkage we see here does create fantastic pressure relief.
Many times latex mattresses can feel like you’re floating “on top” of the mattress as opposed to “in it”.
That’s not the case here. You’re lying in the mattress and there is a noticeable pressure relief created as a result.
Motion Transfer Test
The Diamond Sage has an extremely high level of motion transfer. In our tests, we measured 15.91 m/s². This is more than double the average motion transfer based on all of our tests to date.
The level of motion transfer is documented in the video below.
On average, we have seen 6.50 m/s² of motion transfer. In terms of material choices, the Diamond Sage isn’t granted any favors with the latex hybrid design.
Natural latex has lots of motion, as does a pocketed coil base. It’s no surprise that we see higher levels of motion transfer here.
Max. Acceleration
8.78 m/s²
Min. Acceleration
-7.13 m/s²
Accel. Range
15.91 m/s²
If we look at the motion transfer chart, which visualizes our accelerometer data, we can see the highest levels of motion from 0.00 to 0.22 seconds.
Motion drops off after that but still remains moderately high until 1.06 seconds, before returning to near zero levels. Both the motion peaks and motion duration are less than ideal.
For sleepers who are easily disturbed by motion during the night, this should not be discounted. The Diamond Sage has the 3rd highest motion transfer of any mattress we’ve tested to date.
Response Test
The Diamond Sage has an extremely fast response time. In our tests, we measured a mostly recovered response time of 0.2 seconds and a fully recovered response time of 0.3 seconds.
This is effectively instant and the fastest that it ever gets.
Mostly Recovered
0.2 sec.
Complete Recovery
0.3 sec.
The Diamond Sage is tied for 1st with several other mattresses for the fastest responding mattress we’ve tested to date.
Based on all of our tests to date, on average we have measured mostly recovered response times of 0.52 seconds and an average fully recovered response time of 0.96 seconds. As a result, the Diamond Sage is considerably faster than the average.
The level of responsiveness is documented in the video below.
One of the primary advantages of a latex hybrid is the near-instant response speed. The faster response ensures you never feel stuck, makes it easier to move around on, and improves sex. While latex does not do any favors for motion transfer, it is greatly beneficial for response.
Bounce Test
The Diamond Sage mattress has a very high level of bounce. In our tests, we measured a total bounce height 13.52”. This is 4.22” more bounce than the average of 9.30”.
Max. Depth
6.77″
Max. Rebound
6.75″
Total Bounce
13.52″
As with many of the performance factors we’re testing, bounce is significantly impacted by the material choices and layer design. Latex has lots of bounce, as do pocketed coils.
Max. Sinkage Depth
Max Bounce Height
Together they create an incredibly bouncy and responsive sleeping surface. The high level of bounce is without question negatively impacting the motion transfer.
The level of bounce is documented in the video below.
However, a higher level of bounce is a positive for response, sex, and ease of movement. Typically, I like to see 8-12” of total bounce height.
The Diamond Sage’s 13.52” of bounce is a good bit beyond my preference. Some sleepers will undoubtedly find this bounce level to simply be too high.
In my view, those sleepers who have strong concerns regarding the motion transfer are most likely to find the bounce to be detrimental. For many other sleepers, the benefits of a very high bounce will outweigh the negatives.
Edge Support Test
Edge support for both sitting and lying on the Diamond Sage mattress is excellent. In our sitting edge support tests, we measured 4.0” of total sinkage depth.
Max Sinkage
4.00″
Lying Support
Excellent
This is 0.60” less sinkage than the average of 4.60” (based on all of our tests to date). In general, I like to see 4.0” of sitting edge sinkage or less.
At this sinkage depth, the mattress is still able to create sufficient support to make sitting more comfortable. Oftentimes, latex mattresses severely struggle with sitting edge support. I was pleasantly surprised by the performance level.
The level of edge support while seated is documented in the images below.
Sitting, 140 lbs.
Sitting, 200 lbs.
Without question, the pocketed coil base is doing much of the heavy lifting when it comes to edge support. This speaks to the quality of the coil unit that Diamond is using for the Sage model.
Lying support on the Diamond Sage was equally as impressive. I felt well supported in all sleeping positions when lying directly on the edge of the mattress.
The level of edge support while lying is documented in the images below.
Lying on Edge, 140 lbs.
Lying on Edge, 200 lbs.
This is pretty rare for latex. As with sitting edge support, the Sage creates a surprisingly robust level of support when lying on the edge.
Sex Test
To score sex performance we look at a number of different factors that all play a role in quality sex. Three of the most important factors include:
Sex Bounce
10
Edge Support
9.5
Noise
10
In addition to the factors above, there are a few other things to consider as well, like pressure relief and cooling.
Here’s a look at our complete sex formula:
Sex Score Formula = (Bounce * 0.6) + (Edge Support * 0.2) + (Noise * 0.1) + (Pressure Relief * 0.05) + (Cooling * 0.05)
We use the following scores, plugged into the formula, to derive a sex score for each mattress.
| Sex Factor | Factor Weight | Score |
|---|---|---|
| Bounce | 60% | 10 |
| Edge Support | 20% | 9.5 |
| Noise | 10% | 10 |
| Pressure Relief | 5% | 9.5 |
| Cooling | 5% | 9.5 |
For the Diamond Sage mattress, these individual factors generated a sex score of 9.9.
This is one of the best scores we’ve seen from any mattress to date. The Sage mattress has big bounce, good edges, and a comfortable top surface. It also had good cooling performance and excellent pressure relief as well.
Overall, the Diamond Sage just nails it across the board when it comes to sex.
Pressure Relief Test
Pressure relief on the Diamond Sage mattress is excellent. In our tests, I felt ample pressure relief in all sleeping positions.
Comfort Layer
4.0″
Support Layer
8.0″
While latex can sometimes restrain pressure relief via its often floating “on top” of the mattress feel, we don’t see that here. The Sage has a deeper than average sinkage depth.
This fact, combined with 4.0” of comfort material and a soft 1.0” quilted cover, creates the material recipe for improved pressure relief in a latex hybrid.
The Diamond Sage has a more generalized hug and contour around the body.
However, it’s also a deeper level of sinkage, so the contour ends up being a bit more dramatic than many other latex and latex hybrid mattresses.
All factors considered, I am confident in the pressure relief for the Sage mattress.
Off-Gassing Test
The Diamond Sage mattress had a moderate smell that lasted for 8 days. While this odor wasn’t as strong as many other mattresses out of the box, the smell did linger for longer than usual.
Initial Smell Strength
Moderate
Off-Gassing Period
8 days
This smell is more natural latex and wool smell. It’s not your typical off-gassing smell. There is definitely an odor, but it’s not offensive in the same way that memory foam and poly foam off-gassing is.
Company
The Diamond company has been making mattresses for over 80 years and is well-established in the industry. They offer a 120-night trial period and a lifetime warranty (for the original owner).
| Company Factor | |
|---|---|
| Trial Period | 120 nights |
| Warranty | Lifetime |
| Shipping | Free |
| Returns | Free |
| Country of Origin | USA |
Shipping is free as well as returns. And the mattresses ship straight from a factory in California.
How firm is the Diamond Sage?
The Diamond Sage mattress has a medium firmness of 5 out of 10 on the firmness scale. This firmness is generally suitable for a wide range of sleepers.
It is soft enough for lightweight sleepers to get pressure relief, but still firm enough to also provide support for heavier sleepers.
Support & Sleeping Positions
The Diamond Sage has excellent support. Throughout our tests and in all sleeping positions I felt well supported. The hybrid design and thick 4.0” comfort layer give me great confidence in the overall support abilities.
We measured fantastic objective edge support performance in our tests. Clearly, Diamond is using a higher-performance coil unit.
| Sleeper Weight | Stomach Sleepers | Side Sleepers | Back Sleepers |
|---|---|---|---|
| Under 150 lbs. | Yes | Yes | Yes |
| 150-250 lbs. | Yes | Yes | Yes |
| 250-300 lbs. | Yes | Yes | Yes |
Based on our tests and the material layers I am confident the mattress could support sleepers up to 300 pounds. Beyond 300 pounds and it gets a bit dicey, especially for side sleepers.
Latex and latex hybrid mattresses often struggle to support heavier-weight sleepers. While the mattress may not be ideal for 300+, for all other body weights and sleeping positions I am confident that it will create plenty of support.
Design
The Diamond Sage hybrid is an organic latex hybrid that uses latex foam and a pocketed coil support system. This mattress has a 12″ thickness and a medium firmness of 5 out of 10 on the firmness scale.
Type
Hybrid
Thickness
12″
Firmness
5
Materials
From top to bottom, there are four layers on the Diamond Sage mattress. The layers include the following:
- 1.0″ quilted cover
- 2.0″ natural latex
- 1.0″ natural latex
- 8.0″ pocketed coils
The Cover
The Sage mattress has an organic cotton cover with stitching in a grid pattern. Eucalyptus-colored accent binding at the edge runs around the entire perimeter of the mattress.
On the sides of the Diamond Sage are reinforced handles to help transport the mattress as needed.
The Comfort Layer
At the thickest point, the Diamond Sage mattress has a 4.0″ comfort layer. The top layer is a 1.0″ quilted cover followed by two slabs of latex foam. The first slab is a thicker 2.0″ latex and the following layers is a 1.0″ latex foam with a higher density.
These three layers work together to provide comfort and pressure relief while transitioning into the support layer below.
The Support Layer
Support on the Diamond Sage is made up of an 8.0″ layer of pocketed coils. These coils sit directly below the foam layers and move independently from one another.
This design helps to limit motion transfer and improve pressure relief while weight is more evenly distributed across the surface of the mattress.
Product Evolution
The Diamond Sage mattress was launched in August 2022 along with three other Diamond mattresses—the Flurry Lux, the Lagoon, and the Tailor. Being that it’s a newer mattress, it has undergone no changes since it hit the market.
How is the Diamond Sage Different?
Wondering how the Diamond Sage mattress stacks up against other hybrids on the market or the other Diamond mattresses in the collection? Here are two quick differences to note right off the bat.
#1. Ethically Sourced + Natural
The Diamond Sage mattress includes GOTS and CertiPUR-US certified materials that are ethically sourced and free from harmful substances.
It also has organic cotton, wool, and Talalay latex, all of which are more natural materials than poly foams. If natural materials are an important factor for your next mattress, the Diamond Sage is a solid pick.
#2. High Breathability
Latex foams on the Sage mattress are perforated throughout, which improves cooling performance and enhances breathability.
In addition, the pocketed coil support system also maximizes airflow for the best cooling possible.
Other Mattresses to Consider
Not sure if the Diamond Sage natural mattress is the best pick for you? Check the three top-rated alternate mattresses below.
For Heavier Sleepers
Birch Luxe
9.69 Overall Score
The Birch Luxe hybrid mattress also uses a 2.0″ layer of natural latex and pocketed coils. The Birch has a 1.5″ quilted cover and can support up to 1,000 lbs.
For Limited Motion
Avocado Green
11″ Profile Height
The Avocado Green mattress is better than the Sage mattress in terms of limiting motion transfer but is lacking a bit in the pressure relief department. With only 2″ of comfort material, this wouldn’t be ideal for heavier sleepers.
For Budget
Awara Natural
Natural Materials on a Budget
The Awara hybrid is another natural latex hybrid to consider. It has a 2″ comfort layer, a 10″ full profile height, and a medium-firm feel (6 out of 10). You’ll also save about $500 over the Sage.
Frequently Asked Questions
Still have questions? Check out some of the top FAQs on the Diamond Sage mattress below and get the answers you’re looking for.
Here are the current prices, with any sales or promotions reflected below:
Twin: $1,099
Twin XL: $1,099
Full: $1,399
Queen: $1,499
King: $1,699
Cal. King: $1,799
*Note: Sales prices are subject to change without notice or warning.
